SOUNDS PRODUCED BY THE HEART AND WHAT THEY REPRESENT

S1 = closure of tricuspid & mitral valves (atrioventricular or AV valves)

Louder @ apex
Synchronous with palpation of carotid pulse

S2 = closure of pulmonic & aortic valves (semilunar valves)
Louder @ base

Physiologic splitting of S2— hear closure of aortic then pulmonic separately—the sounds become further apart during inspiration (when take breath in more blood enters into the thorax = more blood into the RV delays closure of pulmonic valve as more blood moves through it & aortic valve closes slightly earlier because less blood coming through it).

Fixed splitting (split in S2 doesn’t change with inspiration but is fixed = diagnostic sign of ASD)

Physiologic splitting of S 3 = normal in some children (early filling)

S 4 = abnormal finding (impaired relaxation of LV)

Sinus arrhythmia: increased HR during inspiration & decreased HR during expiration (normal in children & healthy adults)
Murmurs: due to vibrations within heart chambers